The gene encoding the most abundant protein of purified preparations of Heliothis armigera entomopoxvirus (HaEPV) has been cloned and sequenced. The gene sequence encodes a 40.1K polypeptide with a putative N-terminal 20 amino acid leader peptide, and a single potential N-glycosylation site. Analysis of the protein, which has an apparent M r of 50K on polyacrylamide gels, confirmed post-translational loss of the leader peptide, but showed no evidence ofglycosylation. The protein is related to others previously described from Choristoneura biennis EPV (63 % identity) and Autographa californica nuclear polyhedrosis virus (42 % identity). Polyclonal antiserum raised against a bacterial fusion protein containing the majority of the HaEPV protein specifically labelled HaEPV spindle bodies; confocal laser scanning microscopy suggests that the protein is distributed throughout those viral structures.

SUMMARYInapparent infection of pupae of Apis mellifera by Kashmir bee virus (KBV) and sacbrood virus (SBV) was detected by two different methods, in three consecutive summers, from two widely separated locations in Australia. The prevalence of inapparent KBV infections varied from year to year, in contrast to the more consistent levels of inapparent SBV infection. The implications of inapparent infection for the epizootiology of the viruses in Australia are discussed.

Several groups of large DNA viruses successfully utilise the rich resource provided by insect hosts. Defining the mechanisms that enable these pathogens to optimise their relationships with their hosts is of considerable scientific and practical importance, but our understanding of the processes involved is, as yet, rudimentary. Here we describe an informatics-based approach that uses comparison of viral genomic sequences to identify candidate genes likely to be specifically involved in this process. We hypothesise that such genes should satisfy two essential criteria, namely, that they should be (i) present in those members of a virus family that infect insects, but absent from those that infect other hosts, and (ii) found in at least two unrelated taxa of insect viruses. These criteria currently identify six groups of viral genes, including one that encodes the fusolin/gp37 proteins. Demonstration that the fusolin/gp37 proteins can enhance oral infectivity of insect viruses provides a primary validation of this approach to the examination of insect-virus relationships.

Cucumber green mottle mosaic virus (CGMMV) was detected in samples of cucurbit seed lots intended for entry into Australia for purposes of sowing. CGMMV was detected in 22 of 631 (3.5%) samples tested in 2016; the virus was detected in seeds of cucumber (8 of 102 samples; 7.8%), melon (13 of 393; 3.3%) and watermelon (1 of 57; 1.8%). Virus was found in seed lots identified as originating from Europe, the Middle East, Africa and North, Central and South America. Exclusion of CGMMV from national entry is an important element of Australia's program of official control for the virus.

No abstract